Sheet feeder having suction assist

ABSTRACT

Sheet feeding equipment is provided with a suction means to assist a mechanical spring feeder that engages the trailing edge of the bottom blank in a stack and drive the bottom blank forward to the receiving end of converting equipment operated in conjunction with the feeding apparatus. The suction assist means is provided with a chamber having a relatively deep front portion and an extremely shallow rear portion. The front portion is positioned at the front of the stack and extends rearward to a point just short of the rear edge of the shortest sheets that will be handled by the equipment. The rear portion is open at the rear thereof, so that there is always a substantial opening through which air is sucked into the shallow rear portion and then into the front portion by a suction blower connected to the front portion. The low volume of the rear portion results in high velocity flow therethrough, so that a low pressure region is established well back in the stack to position the bottommost sheet for engagement by the mechanical feeder during its forward stroke.

United States Patent Shields Oct. 23, 1973 SHEET FEEDER HAVING SUCTION ASSIST [75] Inventor: Albert F. Shields, Forest Hills, NY. ABSTRACT [73] Assignee: S&S Corrugated Paper Machinery Sheet feeding equ1pment is provided with a suction Co., Inc., Brooklyn, NY. means to ass1st a mechamcal sprmg feeder that engages the trailing edge of the bottom blank in a stack Filed: July 23, 1971 and drive the bottom blank forward to the receiving [21] Appl. No.: 165,671 end of converting equipment operated in conjunction with the feeding apparatus. The suction assist means is provided with a chamber having a relatively deep U-S- Clt A, front portion and an extremely hallow rear portion [51] Int. Cl B65ll 3/24 Th f t ti i iti d t th f t f th of Search u A, 32, 41, tack and extends rearward to a point just hort of the 271/261 44 R rear edge of the shortest sheets that will be handled by the equipment. The rear portion is open at the rear [56] Relerences Cited thereof, so that there is always a substantial opening UNITED STATES PATENTS through which air is sucked into the shallow rear por- 3,279,7ss 10/1966 Shields 271 44 A x tion and then into the front portion y a Suction 3,5 3,095 1971 w et 1, blower connected to the front portion. The low v01- 3,158,367 11/1964 Tarbuck 271/26 R ume of the rear portion results in high velocity flow 3,265,386 8/1966 Palamenti 271/44 R therethrough, so that a low pressure region is estab- Albert X we back in the tack to position the bottom Priniary Examiner-Evon C. Blunk Assistant Examiner-Bruce H. Stoner, Jr. Attorney-Sidney G. Faber et al.

most sheet for engagement by the mechanical feeder during its forward stroke.

' meme: 0a. 23,1973

3 Sheets-Sheot 1 INVENTOR. ALBERT f". SH/ZZOJ ATTORNEYS Patented" Oct. 23, 1973 I 3,767,186

3 Sheets-Sheet 2 INVE N T OR 455f F 5/;05405 ATTORNEYF SHEET FEEDER HAVING SUCTION ASSIST This invention relates to sheet feeding equipment in general and more particularly relates to a mechanical sheet feeder having a novel suction assist means.

In the paper box making art cutting and creasing presses, automatic folding machines, and other apparatus are operated at high speeds and because of this are provided with automatic high speed sheet feeding equipment. It has been found that prior to feeding of the sheets it is advantageous to arrange them in a stack which is bulk loaded at the top and from which the individual blanks are removed ffom the bottom by automatic feeding equipment.

The prior art has provided both mechanical and suction feeding equipment of this type. My U. S. Pat. No. 2,583,712, issued Jan. 29, 1952, entitled Folding Machine, illustrates a purely mechanical feeding device; a continuous belt suction feeder is described in the J. P. Lopez U. S. Pat. No. 2,995,316 issued Aug. 8, 1961, and entitled Feeding Equipment; a reciprocated suction feeder is illustrated in U. S. Pat. No. 2,862,709, issued Dec. 2, 1958, to P. D. Labombarde, entitled Machine and Method for Feeding Sheets; and a combined mechanical and reciprocated suction feeder is illustrated in my U. S. Pat. No. 3,279,788, issued Oct. 18, 1966, entitled Sheet Feeding Means.

A positive mechanical feeder has proven best in obtaining close registration between feeding equipment and subsequent apparatus which receives blanks from the feeding equipment. Mechanical spring kicker means supported on longitudinally extending pivoted bars, as disclosed in my U. S. Pat. No. 2,902,280, issued Sept. 1, 1959 for a Spring Feeder for Warped Board, does a superior job with board having severe front to back warp. However, for feeding sheets with crosswarp or skew-warp, suction is often required to draw the sheets downward into favorable feeding position. Movable suction feeding devices of the prior art have proven to be relatively costly and/or provide insufficient accuracy of feed, especially at elevated speeds. Stationary suction devices have proven ineffective when suction was applied over a large sheet area as well as when suction was applied over a small sheet area. That is, suction applied over a small area ofa sheet may not draw a badly warped sheet into proper feeding position and suction applied over a large area ofa sheet will result in serious friction drag against the action of the mechanical feeder. Further, set up time is increased for those devices requiring setting of suction area limiting devices in the feed direction.

As will hereinafter be seen, in the apparatus of the instant invention a mechanical feeder of the type illustrated in my aforesaid U. S. Pat. No. 2,902,280 is provided with a suction assist means. Briefly, the latter includes a stationary suction chamber having a relatively deep front portion extending rearward from the front gauge to a point short of the rear edge of the shortest sheets that will be handled by apparatus. The rear portion of the suction chamber, beginning at the rear of the front portion, is extremely shallow throughout the length thereof. The rear of the rear portion is open so that there is always high velocity air flow in the rear portion produced by a suction blower connected to the chamber at the front portion thereof. The suction chamber is sectionalized, and simple manually operated baffle means are provided to select those sections of the suction chamber that will not have suction applied thereto.

Accordingly, a primary object of this invention is to provide a novel suction assist means for a mechanical sheet feeding apparatus.

Another object is to provide apparatus of this type having a suction chamber which is relatively deep at the front thereof and relatively shallow at the rear thereof, the rear portion being opened at its rear end.

Still another object is to provide apparatus of this type in which the suction chamber is provided with a collapsible rearward extension.

A further object is to provide apparatus of this type in which a suction feeder is provided with a suction assist means that produces a downward force on blanks from their lead edges extending back toward their trailing edges so that they will remain in contact with the support surface at the top of the suction chamber while the blanks are engaged by the somewhat raised feeder bar and pushed toward the feed rolls.

These objects as well as other objects of this invention will become apparent after reading the following description of the accompanying drawings in which:

FIG. 1 is a side elevation of sheet feeding apparatus constructed in accordance with teachings of the instant invention.

FIG. 2 is a plan view of the suction assist means in the apparatus of FIG. 1.

FIG. 3 is a rear elevation of the elements of FIG. 2.

FIG. 4 is a fragmentary cross-section taken through line 4--4 of FIG. 1, looking in the direction of arrows 44.

FIG. 5 is a plan view of the suction chamber casting.

FIGS. 6, 7 and 8 are cross-sections of FIG. 5, taken through the respective arrows 66, 77 and 8-8, looking in the respective directions of these arrows.

Now referring to the figures.

Stack 90 of warped board rests upon platform or bed 11 of automatic feeding mechanism 10 with the outwardly bowed side 92 of stack 90 facing bed 11. Side gauges 12 position stack 90 laterally with respect to the feedpath while the front 13 and back 14 gauges maintain stack 90 in the appropriate longitudinal position prior to feeding. Front gauge 13 is vertically adjustable, in a manner well known to the art, and cooperates with lateral bar 15 to define feed space 16 which is high enough to permit the bottommost blank 91 to pass through while holding back the rest of stack 90.

The laterally spaced elements constituting rear gauge 14 are secured to cross member 17 which is positioned on the top side of bed 1 1 and extends between supports 18, 19 which are adjustable both longitudinally and vertically. Reference is made to my aforesaid U. S. Pat. No. 2,902,280 for details of these adjustments. Feed bar carries a plurality of support plates 66 hingedly secured thereto at 67. Support plates 66 extend rearward from feed bar 65 and rest on plate support member 68 which extends laterally across the feed path and is secured to rear gauges 14 below elements 30. Secured to each support plate 66 is a spring kicker 70 which comprises a resilient member 71 extending upwardly at an incline from support plate 66, and a toothed member 72 having teeth 73 along its forward edge and a rounded portion 74 at its rear edge.

With supports 18, 19 raised to a position where elements 30 supporting the rear of stack are raised sufficiently to align the leading edge of the lowest sheet 91 with feed space 16, moving carriage 60 to the rear will position spring kickers 70 to the left of the stack 90 and at a sufficient height so that spring 71 will be lightly loaded as teeth 73 engage the trailing edge of the bottom sheet 91 during the feedout stroke. Movement to the right with respect to FIG. 1 of feed bar 65 insures firm contact between spring kickers 70 and sheet 91, so that the latter may be driven forward through feed space 16 and thereafter engaged by feed rolls 75, 76 and be delivered to a machine for one or more operations.

Support plates 66, disposed between adjacent rear gauges 14, form the hypotenuse of a right triangle having one side of constant length equal to the vertical distance between the plate support member 68 and the top of feed bar 65. The other side is equal to the horizontal distance between hinge 67 and plate support member 68. As feed bar 65 moves forward in its feedout stroke, said other side increases in length bringing about a corresponding increase in the length of the hypotenuse. But the distance between hinge 67 and point 77 to which spring kickers 70 are affixed remains constant so that as a percentage of the hypotenuse, the distance between point 77 and hinge 67 decreases as feed bar 65 moves forward and point 77 is gradually lowered. This, in turn, lowers spring kickers 70, so that the loading of springs 71 does not change appreciably during the feedout stroke since the distance between bed 11 and the bottom of stack 90 also decreases gradually between the back 14 and front 13 gauges. In this manner support plates 66, and, in turn, toothed members 72 follow the slight curvature of stack 90 while bottom sheet 92 is being fed to rollers 75, 76.

Support plates 66 supply a substantially rigid support at 77 for spring kickers 70 so that springs 71 need never be severely loaded. Consequently, the contact pressure between toothed member 72 and the bottom of stack 90 is never sufficient to mar the bottom sheet 91 on the return stroke of feed bar 65. The round surface 74 of toothed member 72 reduces rubbing on the return stroke of feed bar 65.

Bed 11 is the upper surface of main casting 100 and collapsible rearward extension 101 thereof. Hinge 102 connects the forward end of extension 101 to the rear of main casting 100. Spring biased manually releasable latches 103 secured to frame elements 104 extend into notches at the rear of extension 101 to secure the latter in its operative position shown in solid lines in FIG. 1. The dashed line illustration for extension 101 shows the latter pivoted downward to its collapsed or inoperative position. Extension 101 is used in its inoperative position when the front to back distance of sheets being handled is no greater than the front to back distance of main casting 100.

Main casting 100 defines a chamber that is divided into a plurality of elongated compartments, extending parallel to the feed path, by walls 110a-l10h, with the upper edges of these walls together with casting surface 111 forming stack supporting bed 11. The compartment formed between walls 1100 and 110d has a relatively deep forward section 114 and a relatively shallow rear section 115 (FIG. 6). Identical deep and shallow sectioned compartments are formed between walls 1100 and 110b, 1l0b and 1106', 110e and l10f, 110f and g, 110g and 110k. The relatively deep compartment sections 114 are opened at the bottom and are connected directly to transverse manifold 117 connected by conduit sections 118, 119, 120 to the intake of centrifugal blower 121. It is noted that shallow section is open at the rear 115a thereof,just as the extensions of rear compartment sections 115 provided by extension 101 are open at their rear ends for a reason which will be hereinafter explained.

On each side of the center line running through main casting 100, the relatively deep sections 114 of the two outermost compartments are provided with shut-off valves, each consisting of vane 122 fixedly secured near one edge thereof to rotatable shaft 123, which extends externally of manifold 117 and is provided with handle 124 for manual operation of vane 122. When the outboard vane 122 is in its operative position shown in the solid line illustration of FIG. 4, the outboard compartment defined by walls 110g and 110k is isolated from the flow of air generated by suction blower 121, and pressure differentials on opposite surfaces of vane 122 maintain vane 122 in its operative position. Vane 122 is opened by pivoting shaft 123 clockwise with respect to FIG. 4 to bring vane 122 to the phantomed position of FIG. 4. Similarly when the inboard vanes 122 are in their operative positions, the four outboard compartments, two along each side of main casting 100, are isolated from the flow of air generated by suction blower 121.

During the operation of the device illustrated in FIG. 1, it is intended that those relatively deep compartment sections 114 through which there is air flow generated by suction blower 121 will be completely closed by stack 90. Thus, the front to back dimension for the relatively deep section 114 is somewhat shorter than the front to back distance of the smallest blank that will be handled by feeder 10. However, there is a substantial, though small, opening between the bottom of stack 90 and each shallow compartment section 115 to provide an entry for air flow generated by suction blower 121 with such flow being at high velocity in the region below stack 90 and to the rear of relatively deep front section 114. Thus, even though blower 121 operates continuously, there is relatively little loss of air, and suction forces act over substantial portions of sheet 91 from front gauge 13 to the rear of relatively deep front section 114. Thus, it is seen that there is a suction assist force drawing sheet 91 downward. This force consists of the direct suction action at the relatively deep front portion of the chamber, and the action of high velocity air flowing from rear to front in the relatively shallow rear portion of the chamber.

Although in the foregoing this invention has been described in conjunction with preferred embodiments, many variations and modifications will now become apparent to those skilled in the art, and it is therefore preferred that the invention be limited not by the foregoing description but only by the appending claims.

The embodiments of the invention in which an exclusive privilege or property is claimed are defined as follows.

1. In equipment for successively feeding the bottom sheet from a stack of sheets along a generally horizontal feed path to additional apparatus positioned forward of said equipment, first means defining a generally horizontal support for said stack; guide means for maintaining the stack in position transverse to said path, rear gauge means at the rear of said stack, front gauge means positioned above said support to define a space between the lower end of said front gauge means and said support equal to slightly more than the thickness of one sheet and less than the thickness of two sheets, a carriage, means for reciprocating said carriage parallel to said feed path, a mechanical feeder carried by said carriage, said mechanical feeder including feeder means operatively positioned at the rear of said stack when said carriage is in its most rearward position and operatively disposed to engage the trailing edge of said bottom sheet and drive the latter forward as said carriage moves forward from said most rearward position, second means for applying a suction assist force to draw the bottom of the stack downward; said suction assist force acting at said front gauge and for a substantial distance to the rear thereof; said second means including a chamber below said horizontal support and extending rearward from said front gauge means, said horizontal support having opening means communicating with said chamber, third means for generating suction in said chamber, said chamber including a relatively deep front portion and a relatively shallow rear portion extending rearward from said front portion for a substantial distance; fourth means at the rear of said first means defining collapsible rearward extensions for said rear portion and said horizontal support; said rearward extensions forming continuations of longitudinally extending sections of said shallow portion; each of said extensions and each of said sections being generally of the same depth throughout its length.

2. in equipment for successively feeding the bottom sheet from a stack of sheets, along a generally horizontal feed path to additional apparatus positioned forward of said equipment, first means defining a generally horizontal support for said stack; guide means for maintaining the stack in position transverse to said path, rear gauge means at the rear of said stack, front gauge means positioned above said support to define a space between the lower end of said front gauge means and said support equal to slightly more than the thickness of one sheet and less than the thickness of two sheets, a carriage, means for reciprocating said carriage parallel to said feed path, a mechanical feeder carried by said carriage, said mechanical feeder including feeder means operatively positioned at the rear of said stack when said carriage is in its most rearward position and operatively disposed to engage the trailing edge of said bottom sheet and drive the latter forward as said carriage moves forward from said most rearward position, second means for applying a suction assist force to draw the bottom of the stack downward; said suction assist force acting at said front gauge and for a substantial distance to the rear thereof; said second means including a chamber below said horizontal support and extending rearward from said front gauge means, said horizontal support having opening means communicating with said chamber, third means for generating suction in said chamber, said chamber including a relatively deep front portion and a relatively shallow rear portion extending rearward from said front portion for a substantial distance; a manifold interposed between said chamber and said third means, said manifold connected to said chamber at said front portion, longitudinal partition means dividing said chamber into a plurality of compartments; and baffle means having sections selectively movable to operative positions to block communication between said manifold and selected ones of said compartments.

3. Equipment as set forth in claim 2 in which the rear portion is open at the rear thereof whereby the bottom sheet when resting on the horizontal support is ineffective to totally close off said chamber.

4. Equipment as set forth in claim 3 in which the rear portion is generally of the same depth throughout its length.

5. Equipment as set forth in claim 2 in which the front to back dimension of said front portion is slightly less than the front to back dimension of the smallest sheets that will be fed by said equipment.

6. Equipment as set forth in claim 5 in which the rear gauge means normally supports the rear of the stack in a position raised above said horizontal support.

7. Equipment as set forth in claim 2 in which there is a fourth means at the rear of said first means, defining collapsible rearward extensions for said rear portion and said horizontal support.

8. In equipment for successively feeding the bottom sheet from a stack of sheets, along a generally horizontal feed path to additional apparatus positioned forward of said equipment, first means defining a generally horizontal support for said stack; guide means for maintaining the stack in position transverse to said path, rear gauge means at the rear of said stack, front gauge means positioned above said support to define a space between the lower end of said front gauge means and said support equal to slightly more than the thickness of one sheet and less than the thickness of two sheets, a carriage, means for reciprocating said carriage parallel to said feed path, a mechanical feeder carried by said carriage, said mechanical feeder including feeder means operatively positioned at the rear of said stack when said carriage is in its most rearward position and operatively disposed to engage the trailing edge of said bottom sheet and drive the latter forward as said carriage moves forward from said most rearward position, second means for applying a suction assist force to draw the bottom of the stack downward; said suction assist force acting at said front gauge and for a substantial distance to the rear thereof; said second means for applying a suction assist force including a first portion acting in the region of said front gauge and a second portion acting at the rear of the stack; said second portion being derived from relatively high velocity air flow moving along the bottom of the stack from the rear toward the front thereof; said second means including a chamber below said horizontal support and extending rearward from said front gauge means, said horizontal support having opening means communicating with said chamber, third means for generating suction in said chamber, said chamber including a relatively deep front portion and a relatively shallow rear portion extending rearward from said front portion for a substantial distance; said feeder means including a plurality of spring mounted fingers; said rear gauge means normally supporting the rear of the stack in position raised above said horizontal support; said rear portion being generally of the same depth throughout its length; a fourth means, at the rear of said first means, defining collapsible rearward extensions for said rear portion and said horizontal support.

9. Equipment as set forth in claim 8 in which there is a transverse feed slat moved forward and rearward by said carriage; said spring mounted fingers are carried by longitudinal arms pivotally connected at their front ends to said feed slat and at their other ends by said rear gauge means whereby said fingers move closer to said horizontal support as said feed slat moves forward. :k 

1. In equipment for successively feeding the bottom sheet from a stack of sheets along a generally horizontal feed path to additional apparatus positioned forward of said equipment, first means defining a generally horizontal support for said stack; guide means for maintaining the stack in position transverse to said path, rear gauge means at the rear of said stack, front gauge means positioned above said support to define a space between the lower end of said front gauge means and said support equal to slightly more than the thickness of one sheet and less than the thickness of two sheets, a carriage, means for reciprocating said carriage parallel to said feed path, a mechanical feeder carried by said carriage, said mechanical feeder inclUding feeder means operatively positioned at the rear of said stack when said carriage is in its most rearward position and operatively disposed to engage the trailing edge of said bottom sheet and drive the latter forward as said carriage moves forward from said most rearward position, second means for applying a suction assist force to draw the bottom of the stack downward; said suction assist force acting at said front gauge and for a substantial distance to the rear thereof; said second means including a chamber below said horizontal support and extending rearward from said front gauge means, said horizontal support having opening means communicating with said chamber, third means for generating suction in said chamber, said chamber including a relatively deep front portion and a relatively shallow rear portion extending rearward from said front portion for a substantial distance; fourth means at the rear of said first means defining collapsible rearward extensions for said rear portion and said horizontal support; said rearward extensions forming continuations of longitudinally extending sections of said shallow portion; each of said extensions and each of said sections being generally of the same depth throughout its length.
 2. In equipment for successively feeding the bottom sheet from a stack of sheets, along a generally horizontal feed path to additional apparatus positioned forward of said equipment, first means defining a generally horizontal support for said stack; guide means for maintaining the stack in position transverse to said path, rear gauge means at the rear of said stack, front gauge means positioned above said support to define a space between the lower end of said front gauge means and said support equal to slightly more than the thickness of one sheet and less than the thickness of two sheets, a carriage, means for reciprocating said carriage parallel to said feed path, a mechanical feeder carried by said carriage, said mechanical feeder including feeder means operatively positioned at the rear of said stack when said carriage is in its most rearward position and operatively disposed to engage the trailing edge of said bottom sheet and drive the latter forward as said carriage moves forward from said most rearward position, second means for applying a suction assist force to draw the bottom of the stack downward; said suction assist force acting at said front gauge and for a substantial distance to the rear thereof; said second means including a chamber below said horizontal support and extending rearward from said front gauge means, said horizontal support having opening means communicating with said chamber, third means for generating suction in said chamber, said chamber including a relatively deep front portion and a relatively shallow rear portion extending rearward from said front portion for a substantial distance; a manifold interposed between said chamber and said third means, said manifold connected to said chamber at said front portion, longitudinal partition means dividing said chamber into a plurality of compartments; and baffle means having sections selectively movable to operative positions to block communication between said manifold and selected ones of said compartments.
 3. Equipment as set forth in claim 2 in which the rear portion is open at the rear thereof whereby the bottom sheet when resting on the horizontal support is ineffective to totally close off said chamber.
 4. Equipment as set forth in claim 3 in which the rear portion is generally of the same depth throughout its length.
 5. Equipment as set forth in claim 2 in which the front to back dimension of said front portion is slightly less than the front to back dimension of the smallest sheets that will be fed by said equipment.
 6. Equipment as set forth in claim 5 in which the rear gauge means normally supports the rear of the stack in a position raised above said horizontal support.
 7. Equipment as set forth in claim 2 in which there is a fourth means at the rear of sAid first means, defining collapsible rearward extensions for said rear portion and said horizontal support.
 8. In equipment for successively feeding the bottom sheet from a stack of sheets, along a generally horizontal feed path to additional apparatus positioned forward of said equipment, first means defining a generally horizontal support for said stack; guide means for maintaining the stack in position transverse to said path, rear gauge means at the rear of said stack, front gauge means positioned above said support to define a space between the lower end of said front gauge means and said support equal to slightly more than the thickness of one sheet and less than the thickness of two sheets, a carriage, means for reciprocating said carriage parallel to said feed path, a mechanical feeder carried by said carriage, said mechanical feeder including feeder means operatively positioned at the rear of said stack when said carriage is in its most rearward position and operatively disposed to engage the trailing edge of said bottom sheet and drive the latter forward as said carriage moves forward from said most rearward position, second means for applying a suction assist force to draw the bottom of the stack downward; said suction assist force acting at said front gauge and for a substantial distance to the rear thereof; said second means for applying a suction assist force including a first portion acting in the region of said front gauge and a second portion acting at the rear of the stack; said second portion being derived from relatively high velocity air flow moving along the bottom of the stack from the rear toward the front thereof; said second means including a chamber below said horizontal support and extending rearward from said front gauge means, said horizontal support having opening means communicating with said chamber, third means for generating suction in said chamber, said chamber including a relatively deep front portion and a relatively shallow rear portion extending rearward from said front portion for a substantial distance; said feeder means including a plurality of spring mounted fingers; said rear gauge means normally supporting the rear of the stack in position raised above said horizontal support; said rear portion being generally of the same depth throughout its length; a fourth means, at the rear of said first means, defining collapsible rearward extensions for said rear portion and said horizontal support.
 9. Equipment as set forth in claim 8 in which there is a transverse feed slat moved forward and rearward by said carriage; said spring mounted fingers are carried by longitudinal arms pivotally connected at their front ends to said feed slat and at their other ends by said rear gauge means whereby said fingers move closer to said horizontal support as said feed slat moves forward. 